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Rotor Wake Vortex Definition: Initial Evaluation of 3-C PIV Results of the Hart-II StudyAn initial evaluation is made of extensive three-component (3C) particle image velocimetry (PIV) measurements within the wake across a rotor disk plane. The model is a 40 percent scale BO-105 helicopter main rotor in forward flight simulation. This study is part of the HART II test program conducted in the German-Dutch Wind Tunnel (DNW). Included are wake vortex field measurements over the advancing and retreating sides of the rotor operating at a typical descent landing condition important for impulsive blade-vortex interaction (BVI) noise. Also included are advancing side results for rotor angle variations from climb to steep descent. Using detailed PIV vector maps of the vortex fields, methods of extracting key vortex parameters are examined and a new method was developed and evaluated. An objective processing method, involving a center-of-vorticity criterion and a vorticity 'disk' integration, was used to determine vortex core size, strength, core velocity distribution characteristics, and unsteadiness. These parameters are mapped over the rotor disk and offer unique physical insight for these parameters of importance for rotor noise and vibration prediction.
Document ID
20030012791
Acquisition Source
Langley Research Center
Document Type
Other
Authors
Burley, Casey L.
(NASA Langley Research Center Hampton, VA United States)
Brooks, Thomas F.
(NASA Langley Research Center Hampton, VA United States)
vanderWall, Berend
(Deutsche Forschungsanstalt fuer Luft- und Raumfahrt Braunschweig, Germany)
Richard, Hughes
(Deutsche Forschungsanstalt fuer Luft- und Raumfahrt Goettingen, Germany)
Raffel, Markus
(Deutsche Forschungsanstalt fuer Luft- und Raumfahrt Goettingen, Germany)
Beaumier, Philippe
(Office National d'Etudes et de Recherches Aeronautiques France)
Delrieux, Yves
(Office National d'Etudes et de Recherches Aeronautiques France)
Lim, Joon W.
(NASA Ames Research Center Moffett Field, CA United States)
Yu, Yung H.
(NASA Ames Research Center Moffett Field, CA United States)
Tung, Chee
(NASA Ames Research Center Moffett Field, CA United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2002
Subject Category
Aerodynamics
Meeting Information
Meeting: 28th European Rotorcraft Forum
Location: Bristol, England
Country: United Kingdom
Start Date: September 17, 2002
End Date: September 20, 2002
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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